HNHacker News
TopNewBestAskShowJobs

michaelt

39,304 karma · joined June 20, 2012

Greetings from London, United Kingdom! I'm Michael.

http://www.mjt.me.uk

hn@mjt.me.uk

submissionscomments
michaelt··on Claude Code sends your email address to websites
For the user's name it's intentional; they template it into the system prompt with no option to disable it.

For 99% of users, the model knows it's in the /home/joesmith/whatever repo and `git log` shows the last change was by `joe.smith@example.com` - trying to keep the user's identity secret from the model would be nigh-impossible so I think anthropic gave up on even trying.

michaelt··on Goodbye from Salon
Never used Salon myself, but I've also seen this a lot. I assume a lot of these organisations pull in some third-party credit card processing, then when asked "do you want high security and low fraud?" they answer "Yeah of course"

Then the credit card processor asks for card details, full address, phone number, captcha, browser fingerprinting, IP address reputation, validate the payment in your bank's app, reject foreign cards, reject prepaid cards, and so on.

Then a customer like me who is literally at the checkout trying to give them money isn't allowed to.

And they're selling digital goods - pixels are free, a non-paying customer doesn't cost them anything!

michaelt··on Guerrilla bike lanes: San Francisco makes illicit infrastructure permanent (2016)
One such report (in German): https://www.rbb24.de/politik/beitrag/2025/10/zebrastreifen-e... in Eberswalde; apparently firefighters were called in to remove the paint but were unsuccessful in their attempts to wash away the white stripes, and police launched an investigation into suspected interference with road traffic.

And another in Dresden: https://www.youtube.com/watch?v=cQUpQZAeA3w https://www.diesachsen.de/en/politics/a-zebra-crossing-in-dr... "In the summer of 2025, unknown individuals painted a crosswalk on the roadway along the busy street in Neustadt to provide safe access to the Heinrich Schütz Conservatory. The city promptly blocked off the crossing with warning cones [...] stating that unauthorized crosswalks constitute not only property damage but also a dangerous interference with traffic. Furthermore, traffic signs installed without authorization constitute an administrative offense under the Road Traffic Code."

In Los Angeles https://www.latimes.com/california/story/2026-10-16/risking-... "Risking arrest, he paints illicit crosswalks across L.A. ‘We can’t wait any longer’" (initially repainting faded crosswalks, rather than creating new ones)

And an example in Saskatoon, visible only in the 2015 street view image https://maps.app.goo.gl/3zWAkjtSEATswcWm8

michaelt··on OpenAI seems to be silently re-enabling model training on Codex chats
> How is GPT chat different from Gmail of MS Office holding on a lot of sensitive data. LLM-shops are not as trustworthy as cloud providers?

Every LLM company is built on taking a fast-and-loose approach to intellectual property.

Why should the purported legal protections on my LLM conversations be any different to the purported legal protections on those pirated ebooks, scraped newspaper websites, scraped photos, and suchlike?

michaelt··on Supermarket freezers across Europe hit by second suspected cyber-attack
> I still don't see why the expert has to be remote, or why an integrated computer can't do the optimization. Or why it needs to be fiddled with at any significant frequency.

Well, it doesn't. The retailer has a team of techs (or an outsourced vendor) rotating between stores, who are cleaning and replacing air filers, checking lubricants, and so on. They could certainly apply occasional changes to settings.

But to the product manufacturer - the remote management feature literally requires less than $2 of hardware. Hell, it might even save money, by removing screens and buttons.

And the person buying the refrigerator wants something that logs and monitors temperatures, for food safety. And they don't know anything about cybersecurity.

So when the manufacturer says that for just a little more they have a remote monitoring option, which not only provides the monitoring needed for food safety but also reduces maintenance costs - it sounds good to them. They don't realise they're signing up for a multi-million-dollar loss when they get hacked and have to throw out a load of products.

michaelt··on Serbia just elected the world's brainiest parliament
Maybe so, but most politicians need to get votes. Not all of them go as far as GWB-style "the kind of guy you could have a beer with" but they all know there's no benefit to being contemptuous of any popular entertainment.

An academic can be an ivory tower type who thinks sports matches, superhero movies, social media and star musicians are a waste of time.

But politicians who think the Superbowl is a waste of time, that star wars is for children, and that Taylor Swift's music sucks pretty quickly figures out sharing those opinions loses far more votes than it gains.

michaelt··on Serbia just elected the world's brainiest parliament
Some character traits that are useful to academics are useful to politicians; others are kinda the opposite of what politicians need.

Intelligence? Problem solving? Understanding statistics? Speaking in front of rooms full of people? Communicating complex ideas clearly? Useful for both jobs.

But an academic can be bookish, shy or haughty. Pursuing your own ideas is actively encouraged. There are arguments - but the main audience for the debates are other academics. They needn't collaborate on research with anyone they don't want to, and when they do collaborate everyone has the same destination in mind even if they disagree about the route to get there. When dealing with students, they've all chosen to be there, passed exams and paid money. The work is mostly low-medium stakes, with time to get important things right. And of course they have excellent job security.

Politicians, though? Gotta love campaigning and talking to voters. Gotta all get together behind the party's national platform. Even colleagues in your party are rivals because everyone wants the top job. 'Debates' all about playing to the audience and getting 3-second soundbites for social media, not engaging with the substance of arguments. No choice in who you collaborate with, including people with deep-seated disagreements about things like tax, debt, spending. Gotta represent voters many of whom hate you. Do well at the job and high stakes things you didn't even do get blamed on you, like train crashes and oil markets getting expensive. Oh, and every 4-5 years you're fired and get to re-apply for your job.

michaelt··on Longitudinal Changes InWearable-Captured PhysiologyBefore Sudden Cardiac Death
> Why would we expect calorie burn to be related to steps and heart rate? How could a wearable measure energy expenditure?

A lot of exercise equipment manufacturers will display very approximate numbers, based on assumptions the user can adjust if they want (but they seldom do).

If you jump on a treadmill at the gym and set it to a brisk walk, it'll show you a 'calories burned' count that goes up by 7 calories per minute based on your speed and an average adult's weight.

It doesn't have to be all that accurate to motivate the user to just do 5 more minutes, and to put a checkmark on a product feature list.

michaelt··on Longitudinal Changes InWearable-Captured PhysiologyBefore Sudden Cardiac Death
If you look at supplemental table S6 (which is admittedly inconvenient because it's a separately downloaded MS Word document) you get this:

S6. Summary of indoor cycling (Peloton) workouts by year (2018–2025)

  2018 (age 70): 11 workouts, 20 min, 171 watts
  2020 (age 71): 14 workouts, 60 min, 175 watts
  2021 (age 72): 140 workouts, 30 min, 177 watts
  2022 (age 73): 164 workouts, 20 min, 167 watts
  2023 (age 74): 73 workouts, 30 min, 187 watts
  2024 (age 75): 59 workouts, 45 min, 165 watts
  2025 (to march): 69 workouts, 30 min, 165 watts
In 2021-2022 the patient was doing 2-3 workouts a week on a stationary bicycle. And 177 watts for 30 minutes is solid, at age 72.

Going up to 5-6 workouts per week is a step up, but this wasn't an inexperienced rider. And who knows how much outdoor cycling they did, which the Peloton wouldn't have recorded?

michaelt··on Binance-hacker-1029 – $5.6B stolen from Binance
I myself was held prisoner by John Searle for 20 years, my only contact with the outside world by notes slipped under the door written in Chinese - a language I do not speak.
michaelt··on Binance-hacker-1029 – $5.6B stolen from Binance
That hasn't been true for years.

Back in 2016 a then-huge Ethereum smart contract called "The DAO" [1] had a loophole that let an attacker extract a third of all the funds.

But a lot of the developers and miners had either lost money themselves, or had friends who'd lost money, or felt the embarrassing incident was devaluing their own Ethereum holdings. So they decided to allow takesies-backsies.

There's probably a philosophical lesson there about power and who the rules really apply to.

[1] https://en.wikipedia.org/wiki/The_DAO

michaelt··on Code-execution flaw in UEFI firmware threatens most servers on planet Earth
Yes - all the times I've seen PXE boot used, the usage has been "Hold F12 during boot to reformat the disk and re-install the OS from scratch"

Which is something that happens inside a trust boundary. After all, if an untrusted third party gets to install your OS it's game over, UEFI bug or not.

And consumer devices often don't have a network card - or come with PXE disabled in the BIOS.

michaelt··on Who killed the EV cert? A browser whodunit for Halloween
> The Stripe we are all familiar was incorporated in Delaware, so there was not a collision. But both companies were described by a browser as “Stripe, Inc.”

As I recall, EV certificates also had the 'problem' that a lot of companies trade under names that aren't their full legal name, making the EV cert confusing. To use modern examples, twitter.com having an EV cert for "Space Exploration Technologies Corp", google.com having an EV cert for "Alphabet Inc" and suchlike.

michaelt··on Who Cares Whether Academics Use AI to Write?
While I broadly agree, I'm sympathetic to making some use of using AI when writers with an intermediate command of English are publishing papers in English.

Because, as a German academic once explained to me (years before the rise of LLMs), if you want your ideas to be influential you need people to read your papers, and you get a heck of a lot more readers when publishing in English than you do publishing in German.

Unfortunately, it's much more difficult to draw a clear line once you start allowing some AI writing tools.

michaelt··on I Built a Stereo Vision Board for Hardware Hackers
While I wouldn't say opencv makes it simple they do provide functions like findChessboardCorners, CharucoDetector, stereoCalibrate - even code to generate printable calibration patterns.

And these days, you can get an LLM to stitch those functions together

michaelt··on Full Disk Encryption on Fedora with TPM2
I mean, Linux has perfectly good FDE - just the user has to type in their password at boot, no TPM involved.

And it's been possible to get Windows-style self-unlocking FDE for 10+ years, such as by using Ubuntu Core - it just costs a bit, and most users aren't willing to pay $$$ to type one less password.

The design of the TPM makes much more sense for a closed-source operating system, where making it impossible to run a non-microsoft-signed OS protects you against rootkits. Open source OSes don't get that benefit, and the remaining benefits are very minor (and come with big downsides) so I can see why open source developers weren't in a hurry.

michaelt··on Every AI model has the same "controversial" take on humans
If you asked 100 programmers for their most controversial take on programming, would you expect them all to say the same thing?
michaelt··on Woman charged with computer fraud due to scam CashApp account being in her name
> False dichotomy?

Yes, I'm trying to say it's a false dichotomy. There are plenty of other ways you could organise a justice system, many of which would lead to more just results.

For example - a fixed price system. 8 hours wages from the two parties to the dispute buys 30 minutes with one judge and two lawyers. More than enough time to deal with a minor matter like a scratched car. Or if you prefer a continental-style inquisitorial system, you can lose the lawyers and have 90 minutes with a judge. The fees mean judges and lawyers take home 5x the average salary.

michaelt··on Woman charged with computer fraud due to scam CashApp account being in her name
Perhaps there are alternatives other than "small crimes go unpunished" and "people make false admissions of guilt, pressured by the ruinous cost of the justice system, 300 jurors needed for a single trial"

If we've got a Lamborghini justice system, delivering amazing performance to people with a spare $250k and doing nothing for anyone else - some would say that's not the right price/performance trade off.

michaelt··on eMudhra intermediate CA compromise
> users are running 5+ year old system CA bundles, which are not sufficient for connecting to some of the most popular API endpoints out there.

Really?

I was under the impression that when a new CA starts operating, they get their certificates cross-signed by older CAs, to ensure their certificates work on older devices? Lets Encrypt did something like that [1] - although they started operating in ~2015, their certificate chain started with a root valid from October 2000 to October 2021 [2]

After all, many website operators want users to be able to connect even if they're using prehistoric Android versions.

You can access Wikipedia with Android 4.4 which was released 13 years ago [3] (although apparently not on the slightly older Android 4.3)

[1] https://letsencrypt.org/2015/10/19/lets-encrypt-is-trusted [2] https://scotthelme.co.uk/lets-encrypt-old-root-expiration/ [3] https://www.ssllabs.com/ssltest/analyze.html?d=en.wikipedia....

michaelt··on eMudhra intermediate CA compromise
Every cert an attacker issues with eMudhra's private key has to appear in the CT logs if they want it to validate in a modern browser.

But if you only want to MITM the connection used by 'pip' to install python wheels - that doesn't check for CT records at all.

michaelt··on Academics have a duty to defend open knowledge systems like Wikipedia
> it's tough to defend when their policies allow factually incorrect content to remain just because it appears on a third-party source that the editors consider reliable.

I feel this is the kind of discussion that would really benefit from a number of concrete examples.

michaelt··on How I got over 300 Tor exit nodes removed
> Not only was it detected immediately thanks to SSH printing that huge banner on MITM attacks

The thing is, that only helps Tor users who are happy for their PC to contain evidence of what they were doing over Tor (such as a known hosts file listing).

If your security requirements are so high your PC contains no evidence whatsoever of what you were doing over Tor, you wouldn't get the banner.

michaelt··on How I got over 300 Tor exit nodes removed
> The biggest question is still how they got into all those servers in the first place.

The simplest way is to just launch the servers yourself, using a cloud provider. Tor is completely OK with exit node operators being anonymous, and with exit nodes running in cheap cloud data centres.

michaelt··on Ask HN: How to deal with shipping AI-written code you don't understand?
Except in this case the label on the eggs says "Eggs may occasionally be poisonous. Users should not rely on eggs to be safe, and should carefully scrutinise eggs before and during cooking. Bob's Farm accepts no liability for injuries resulting from making omelets with our eggs."
michaelt··on Ask HN: How to deal with shipping AI-written code you don't understand?
I find the problem with "lots and lots of testing" as a solution - (assuming by that you mean lots and lots of automated testing) is it invites lots and lots of lines of code - making code reviews even more challenging.

If someone finds it burdensome to review my 50-line AI-generated bug fix, adding 200 lines of tests only gives them more lines to review.

michaelt··on I electrified my push scooter with a power drill
I used a lower price electric drill to polish some stainless steel, and after a single hour of continuous operation it was never the same again.
michaelt··on Gold is now the top U.S. export
> How many aircraft can the world need that it commonly tops the export chart of the wealthiest country?!

Consider how many American companies exclusively manufacture in the far east.

If a European buys a product "made by" Apple or nvidia or Nike or Levis - that's not an American export, it's an export of Indonesia, China, Vietnam, Taiwan, or wherever. America still gets the profits, though.

michaelt··on Claude reveals ECDSA curve origins
Thank god NIST gifted us Dual_EC_DRBG, so I still have a NIST Elliptic Curve effort I can sneer at dismissively.

RSA was good enough for my grandfather, and it's good enough for me.

michaelt··on BIPM decides to stop adding leap seconds to UTC
As I understand it, almost nobody was actually using UTC anyway.

Almost every programming language and database I've ever used assumes 86400-second days, ignoring leap seconds. And one of the popular ways of applying leap seconds was a 'smear' [1] running every clock slightly fast for about 24 hours, rather than having a 61-second minute.

So instead of UTC we actually all use a slightly elastic timescale with the name of UTC, most of the time aligned with UTC, but with the linearity of TAI, and the desirable property that if I'm going to a concert at 19:00 in a year's time and a leapsecond is announced and implemented in the interim, the concert doesn't change to 18:59:59.

[1] https://developers.google.com/time/smear

Page 1 of 34Next →